Homeopathic remedies, also known as homeopathy, are a type of alternative medicine based on the principle of "like cures like"—the idea that a substance that causes symptoms in a healthy person can be used in diluted form to treat similar symptoms in a sick person. The term "homeopathy" is derived from the Greek words homoios (similar) and pathos (suffering or disease). In Hebrew, homeopathy is referred to as הומיאופתיה (homioapatya), in German as Homöopathie, and in French as homéopathie. Homeopathic remedies are prepared by serial dilution, where a chosen substance is repeatedly diluted in alcohol or distilled water, often accompanied by forceful striking on an elastic body, a process called succussion. The final product may not contain any molecules of the original substance. Proponents claim that homeopathic remedies can treat a wide range of health conditions, but numerous scientific studies and systematic reviews have found that homeopathic remedies are not effective beyond a placebo effect. The use of homeopathy is controversial, and many mainstream medical organizations, including the World Health Organization, discourage its use for serious or life-threatening conditions.